﻿/*
 * Swipe 1.0
 *
 * Brad Birdsall, Prime
 * Copyright 2011, Licensed GPL & MIT
 *
*/

window.Swipe = function(element, options) {

    // return immediately if element doesn't exist
    if (!element) return null;

    var _this = this;

    // retreive options
    this.options = options || {};
    this.index = this.options.startSlide || 0;
    this.speed = this.options.speed || 300;
    this.callback = this.options.callback || function() {};
    this.delay = this.options.auto || 0;
    this.unresize = this.options.unresize; //anjey

    // reference dom elements
    this.container = element;
    this.element = this.container.children[0]; // the slide pane

    // static css
    //this.container.style.overflow = 'hidden'; //by anjey
    this.element.style.listStyle = 'none';

    // trigger slider initialization
    this.setup();

    // begin auto slideshow
    this.begin();

    // add event listeners
    if (this.element.addEventListener) {
        //by anjey
        this.element.addEventListener('mousedown', this, false);
  	 
        this.element.addEventListener('touchstart', this, false);
        this.element.addEventListener('touchmove', this, false);
        this.element.addEventListener('touchend', this, false);
        this.element.addEventListener('webkitTransitionEnd', this, false);
        this.element.addEventListener('msTransitionEnd', this, false);
        this.element.addEventListener('oTransitionEnd', this, false);
        this.element.addEventListener('transitionend', this, false);
        if(!this.unresize){ // anjey
            window.addEventListener('resize', this, false);
        }
    }

};

Swipe.prototype = {

    setup: function() {

        // get and measure amt of slides
        this.slides = this.element.children;
        this.length = this.slides.length;

        // return immediately if their are less than two slides
        if (this.length < 2) return null;

        // determine width of each slide
        this.width = this.container.getBoundingClientRect().width || this.width; //anjey
        // return immediately if measurement fails
        if (!this.width) return null;

        // hide slider element but keep positioning during setup
        this.container.style.visibility = 'hidden';

        // dynamic css
        this.element.style.width = (this.slides.length * this.width) + 'px';
        var index = this.slides.length;
        while (index--) {
            var el = this.slides[index];
            el.style.width = this.width + 'px';
            el.style.display = 'table-cell';
            el.style.verticalAlign = 'top';
        }
        // set start position and force translate to remove initial flickering
        this.slide(this.index, 0); 

        // show slider element
        this.container.style.visibility = 'visible';

    },

    slide: function(index, duration) {

        var style = this.element.style;

        // fallback to default speed
        if (duration == undefined) {
            duration = this.speed;
        }

        // set duration speed (0 represents 1-to-1 scrolling)
        style.webkitTransitionDuration = style.MozTransitionDuration = style.msTransitionDuration = style.OTransitionDuration = style.transitionDuration = duration + 'ms';

        // translate to given index position
        style.MozTransform = style.webkitTransform = 'translate3d(' + -(index * this.width) + 'px,0,0)';
        style.msTransform = style.OTransform = 'translateX(' + -(index * this.width) + 'px)';

        // set new index to allow for expression arguments
        this.index = index;

    },

    getPos: function() {
    
        // return current index position
        return this.index;

    },

    prev: function(delay) {

        // cancel next scheduled automatic transition, if any
        this.delay = delay || 0;
        clearTimeout(this.interval);

        // if not at first slide
        if (this.index) this.slide(this.index-1, this.speed);

    },

    next: function(delay) {

        // cancel next scheduled automatic transition, if any
        this.delay = delay || 0;
        clearTimeout(this.interval);

        if (this.index < this.length - 1) this.slide(this.index+1, this.speed); // if not last slide
        else this.slide(0, this.speed); //if last slide return to start

    },

    begin: function() {

        var _this = this;

        this.interval = (this.delay)
          ? setTimeout(function() { 
              _this.next(_this.delay);
          }, this.delay)
          : 0;
  
    },
  
    stop: function() {
        this.delay = 0;
        clearTimeout(this.interval);
    },
  
    resume: function() {
        this.delay = this.options.auto || 0;
        this.begin();
    },

    handleEvent: function(e) {
        var that = this;
        if(!e.touches){
            e.touches = new Array(e);
            e.scale = false;
        }
        switch (e.type) {
            // by anjey
            case 'mousedown': (function(){
                that.element.addEventListener('mousemove', that, false);
                that.element.addEventListener('mouseup', that, false);
                that.element.addEventListener('mouseout', that, false);
                that.onTouchStart(e);
            })(); break;
            case 'mousemove': this.onTouchMove(e); break;
            case 'mouseup': (function(){
                that.element.removeEventListener('mousemove', that, false);
                that.element.removeEventListener('mouseup', that, false);
                that.element.removeEventListener('mouseout', that, false);
                that.onTouchEnd(e);
            })(); break;
            case 'mouseout': (function(){
                that.element.removeEventListener('mousemove', that, false);
                that.element.removeEventListener('mouseup', that, false);
                that.element.removeEventListener('mouseout', that, false);
                that.onTouchEnd(e);
            })(); break;
    	
            case 'touchstart': this.onTouchStart(e); break;
            case 'touchmove': this.onTouchMove(e); break;
            case 'touchend': this.onTouchEnd(e); break;
            case 'webkitTransitionEnd':
            case 'msTransitionEnd':
            case 'oTransitionEnd':
            case 'transitionend': this.transitionEnd(e); break;
            case 'resize': this.setup(); break;
        }
    },

    transitionEnd: function(e) {
        e.preventDefault();
        if (this.delay) this.begin();

        this.callback(e, this.index, this.slides[this.index]);

    },

    onTouchStart: function(e) {
    
        this.start = {

            // get touch coordinates for delta calculations in onTouchMove
            pageX: e.touches[0].pageX,
            pageY: e.touches[0].pageY,

            // set initial timestamp of touch sequence
            time: Number( new Date() )

        };

        // used for testing first onTouchMove event
        this.isScrolling = undefined;
    
        // reset deltaX
        this.deltaX = 0;

        // set transition time to 0 for 1-to-1 touch movement
        this.element.style.MozTransitionDuration = this.element.style.webkitTransitionDuration = 0;

    },

    onTouchMove: function(e) {

        // ensure swiping with one touch and not pinching
        if(e.touches.length > 1 || e.scale && e.scale !== 1) return;

        this.deltaX = e.touches[0].pageX - this.start.pageX;

        // determine if scrolling test has run - one time test
        if ( typeof this.isScrolling == 'undefined') {
            this.isScrolling = !!( this.isScrolling || Math.abs(this.deltaX) < Math.abs(e.touches[0].pageY - this.start.pageY) );
        }

        // if user is not trying to scroll vertically
        if (!this.isScrolling) {

            // prevent native scrolling 
            e.preventDefault();

            // cancel slideshow
            clearTimeout(this.interval);

            // increase resistance if first or last slide
            this.deltaX = 
              this.deltaX / 
                ( (!this.index && this.deltaX > 0               // if first slide and sliding left
                  || this.index == this.length - 1              // or if last slide and sliding right
                  && this.deltaX < 0                            // and if sliding at all
                ) ?                      
                ( Math.abs(this.deltaX) / this.width + 1 )      // determine resistance level
                : 1 );                                          // no resistance if false
      
            // translate immediately 1-to-1
            this.element.style.MozTransform = this.element.style.webkitTransform = 'translate3d(' + (this.deltaX - this.index * this.width) + 'px,0,0)';

        }

    },

    onTouchEnd: function(e) {

        // determine if slide attempt triggers next/prev slide
        var isValidSlide = 
              Number(new Date()) - this.start.time < 250      // if slide duration is less than 250ms
              && Math.abs(this.deltaX) > 20                   // and if slide amt is greater than 20px
              || Math.abs(this.deltaX) > this.width/2,        // or if slide amt is greater than half the width

        // determine if slide attempt is past start and end
            isPastBounds = 
              !this.index && this.deltaX > 0                          // if first slide and slide amt is greater than 0
              || this.index == this.length - 1 && this.deltaX < 0;    // or if last slide and slide amt is less than 0

        // if not scrolling vertically
        if (!this.isScrolling) {

            // call slide function with slide end value based on isValidSlide and isPastBounds tests
            this.slide( this.index + ( isValidSlide && !isPastBounds ? (this.deltaX < 0 ? 1 : -1) : 0 ), this.speed );

        }

    }

};